Hello
Is there any way to extract the measures data to a csv file? Also, when I plot out the measures, is there away to change the axis from linear to log?
Thanks
Rich Hilson
Hello
Is there any way to extract the measures data to a csv file? Also, when I plot out the measures, is there away to change the axis from linear to log?
Thanks
Rich Hilson
Hello,
Is there a way to overlay fringe results with isoline (Creo3)?
I want to have a black line separation between my color spectrum.
Thank you for any tipp
Hello!
Supposing to have square with hole,
I would like to fixe to the ground constraint at the middle of your length
and at the center of the internal circumference (as show in image below)
I thought to create an external point ,
then create a rigid link between internal surface and the point
When I try to insert a displacement on the point, I obtain this error message
What is the error?
Thank you
Good Week!
Federico
Hello,
I have a simulation including a stationary body and a moving body. There is a contact between them. I often see the warning: "Excessive displacement at contact region". A software suggests smaller time step but I can not reduce it. The full moving process is described with 100 step and the software does not allow to define more...
1. What does it mean exactly the excessive displacement at the contact? Is the time step too large compared to distance between two mesh nodes? If I increase this distance (element size) - instead of time step reduction - is it correct?
2. How can I define more steps under "User define output step"?
Thanks a lot your help;
Roland
Hello,everyone!
I find something newer in Creo 4.0 batch file".bat" than Pro/E 5.0,there is a parameter"-results_io_cache_size 1024",who can tell me how to set the value so that it will reduce the elapsed time? Thanks in advance!
Good Morning All
I have been doing a project in Creo for the last few months and this is the first time I come across this software, I must say that this peice of software is just wonderful. I wanna praise teh software a bit more but maybe lcox that will require an eassay or something, anyways let me get to the point straight away.
I attached a picture of my model. Its a support and motion system for those two magnetic sheath coils as you can see from the picture. There is an impact force for 70 t vertically and 20 t horizontally and plus the torques. Everything is set in place. Materials, forces/torques, constraintes, interafaces.etc. As for the materials there are vertical and horizontal dampers in the model. They have a different material with a different Young's Modulus and poissons ration( as it should be). I have used NBR(I think thats what its called) rubber. With the help of your online resources and others help Im glad I can now do static analysis. Modal Analysis and even dynamic time analysis(I have the needed input function for the structure). Im familiar with all the steps and all.But wanna learn more actually I need to learn more, thats why I love doing this , you always get to learn more.
Okay. Everything in place. My question is. How to or Is it possible to calculate the damped forces and also the stiffnnes of the material Im using for damping. Thing is I need the damped forces to do the static analysis so that the structure of the system stays in limits as needed. Stiffness I just want to know out of curiosity. I mean its not a fault to learn more right?..
Thank you for reading the long question and I will be thankful for any kind of Help.
Have a great day!
PS: This thing is huge like the cylinder is 10m longer. You can imagine the rest with respect to the cylinder.
I'm having another try at using fasteners, but like most things in Creo it's pretty tricky without a training course or an expert on hand.
The diagnostics during meshing are returning the fatal error "Creo Simulate cannot pair the linked assembly elements near the highlighted entities. Try modifying the geometry to correct the problem." It meshes fine with the fasteners suppressed.
Here's one of the offending fasteners, with its details:
The surface highlighted to go with the error message is the face of the rear component, that the flange is clamped up against.
What's even more frustrating is that I had it working with just a couple of fasteners, so I added the rest; it then stopped working, so I tried a few things, then went back to just a couple, and now it still doesn't work!
Could someone give me some pointers on how I should be using fasteners in this situation, please? What is the mesher trying to do due to the fastener that causes it to fail?
Good Morning from Harbin Institute of Technology(HIT) of China, [[ I am a foreigner though ]]
I am trying to understand how to interpret output from a normalized input force-time curve.
My purpose: to get the displacement and stress over the model or at a point when this curve is applied as an input.
Load_Set: the load set have vertical and horizontal forces of like 5e6 N etc...point is really huge forces. plus very high torques.
What I am doing: I did a modal analyses as required and it went pretty well. (output is mass-normalized), then I tried a Dynamic-Time analyses(damping coefficient is 4%) with this function I mentioned above.
Below is the function and the result I got.
Problem: I previously did a static analyses and it gave displacements like ~15 mm. static analyses won't have the damping effect of the dampers as far as I understand but in dynamic analyses it will. I did test on a small subject and it showed the damping effect when the material is set correctly. I think its so obvious for a sane mind that with that huge forces and torques that much small output for displacement is impossible..I once measured stress and it was like 0.2 Mpa. Is it because of the input curve? also can I use the impulse function to get the results, I mean will it be OK?(highly doubt it will be, but I am not sure). I am new to this field and trying to learn. Please do help me out here, Please tell me what I am missing or what I am doing wrong.
Why I am doing this: I need to know the displacement and acceleration, maybe from acceleration I can obtain the damped forces. I need these damped forces to design the power-screw drive which controls the motion of the coils. It can't be design without knowing the damped forces because the Maximum load for the spindle depends on that.
PS: That force in the function is sure normalized as u can see. As in Chinese they say 峰值归一化的力. I attached a paper about this system( not related to my field) just to show this is a real thing.
Good morning,
Time ago I created a contact interface kind surface-surface using intent surfaces, where one of the "intent surfaces" was a group of surfaces.
I'm trying ti repeat this operation but I'm not able to select more than one surface per contact surface.....doea anybody can help me?
Thanks a lot
Hello!
I would like to prevent the interprenetation of solids, that are "linked" by fasteners...
You have any idea?
Thank you
Good Life
Federico
So, inspired by Roland Jakel's presentation, I thought I'd revisit an old analysis and try to re-run it using the fastener functionality.
Unfortunately, the analysis ran with "The fastener is invalid" warnings, and resulted in no loads (despite specifying preload).
The model is slightly unusual in that there is a deliberate gap which the bolts should pull down once tightened, so I closed the gap to make the surfaces coincident, but this made no difference.
The clearance holes are chamfered on both sides, so I suppressed these chamfers (and reinstated the gap) then redefined the fastener references, only to be told that "The fastener references cannot lie on the contacting surfaces." Well, a) there's a gap so technically the surfaces aren't contacting, and b) how else am I supposed to select the references, if I can't select the open edge of the tapped hole?
On a related note, it tells me that I can't put a 6 mm fastener into my M6 tapped (Ø5) hole - should I be modelling my tapped holes at the major diameter, or is the root diameter of the screw thread appropriate?
Bonjour,
Je cherche à comprendre comment créer un lien rigide entre 2 perçages. Pour cela, j'ai créé:
- une poutre encastrée reliée par 2 perçages à une poutre elle même soumise à un effort de flexion
- un point au centre de chacun des perçages
- une idéalisation de ressort entre chaque point et la surface interne du perçage lui correspondant
Mais cela ne fonctionne pas: "Le modèle ne contient pas suffisamment de restrictions pour l'analyse. Vérifiez les liaisons d'éléments, les propriétés et les restrictions des entités en surbrillance."
Comment dois je m'y prendre pour créer un lien rigide à partir de points? (Je ne veux pas créer de liens rigides entre les surfaces des perçages, car les contraintes obtenues faussent mes résultats).
Je travaille sous Creo Simulate 3 avec la licence de base. Est ce qu'une licence avancée me simplifierait la tâche?
Merci par avance de vos réponses.
Hello All,
I am trying to develop a feel for the behaviour of Creo3.0's finite friction.
So starting with a simple model
Text book concludes no sliding.
Reality tells us that the pressure distribution is not like the text book Amongst other things,the load pulling the green block acts a distance above the surface and not in the surface. It's this estimate of reality we want.
We know that the blocks are elastic (even though they are steel) and therefore one should expect a high (theoretically enormous) stress around the perimeter of the green block ... and maybe in part where problems begin.
The values chosen should ensure no sliding.
I used brick elements (tets give poor pressure plots and bricks provide a more 'stable' solution)
The problem is very 'sensitive' to the initial time step.
It will not solve using the default 0-1 ramp function with much oscillation of the residual norm, contact area reducing to zero followed by bisection after bisection then failing. The load factor is reduced to
Load Factor: 0.000195313
*** A fatal error has occurred. ***
There are 3 directions to explore
1. Load step refinement
2. Mesh refinement
3. This is a load rather than displacement controlled problem
LOADSTEP REFINEMENT:
With 10% timesteps, bisection still occurs but I get a solution and the results don't look right. Unrealistic displacement of the green block and a tangential force measure magnitude of 0.00757N where the applied load is 0.1N. The load factor is reduced by the software:
** Warning:
Excessive motion detected at contact regions.
Cutting load step size.
Load Factor: 0.025 (presumably of my 10% step)
The interface force is 7.48e-2 whereas the normal force applied is 2000N (presumed: the interface force measure is normal to the surface)
All the movement occurs in the first time step.
All this suggests poor mesh/loadstep selection.
With 1% loadsteps there is some similar behaviour, just many more graph points (not all shown) and a lot more time (14658.75 secs vs 2246.68 secs)
There is a much smaller movement, with nearly all of it happening in the first loadstep with a very small increase in displacement each step after the first time step.
but now the tangential force measure doesn't stack up. The block is being pulled with 0.1N. The integral of tangential friction force across the contacting face cannot exceed the applied load.
Interface1_any_slippage: 2.456282e-01
Interface1_area: 2.000001e+03
Interface1_average_slippage: -8.653680e-02
Interface1_complete_slippage: -2.126610e-01
Interface1_force: 3.672802e+00
Interface1_max_tang_traction: 4.273336e-01
Interface1_tang_force: 4.515394e-01
the applied load pulling the block was 0.1N, the tang force is 0.45N
The resultant pressure load applied was 2000N, interface force is 3.67N
I should (and forgot) to create a ground constraint measure. Grrr.
So this is a mesh refinement thing? Should we have a finer mesh at the loaded edge? Should rounds be applied?
MESH REFINEMENT
Try tets? smaller bricks? Mesh is everything in Non-linear.
DISPLACEMENT CONTROL
A lot of problems have to be turned 'upside down'. Rather than applying the load an enforced displacement constraint is used such that a run-away condition is cannot be encountered; the model is always fully constrained. The reaction at the constraint is the load that would have otherwise been applied. This is how the examples posted on the learning connector (and others) work.
The problem with this is that the potential movements are so small. The green steel block is 50mmx40mmx10mm and if it's entire length 50mm length was involved in the stretching, it would have a stiffness of 10x40x200,000/50=1.6e6 N/mm. When the full load of 0.1N is applied then the extension would be 6.35e-8mm. The actual extension will be less than this as is seems reasonable that slip would only occur local to the loaded face initially with the rest of the contact interface effectively isolated and not moving. Surely therefore the enforced displacement constraint must have steps in the order of 10e-9mm or lower. I then have to question the mesh resolution again even though I know there are polynomials underneath.
So the fuzzy question is, There will have been much testing on simple models such as this. Can we have some guideline re mesh, loadsteps and where it is not appropriate to apply finite friction, benchmark models?
Could my meanderings above be unpicked for a better understanding? and apologies in advance for any glaring mistakes, it has been a long (interesting) week.
En passant, what is the practical difference between asking for full results at user defined steps on the output tab and having a load that is factored by a function?
Thanks for getting this far
bfn
Hi,
I'm running into issues trying to run a cyclic symmetry analysis on one part of a large disk - whenever I try to mesh the model, it returns the following error:
The requested shape change invalidates the Cyclic Symmetry
constraints associated with the highlighted geometry. Delete
these constraints if the requested shape change is required.
Source: AutoGEM
What shape change is this referring to, and why does that invalidate the constraint?
The model I'm working with is cut into pieces at a slight angle - so the faces selected for cyclic symmetry are not perpendicular to the 'front' face of the disk model. Would this cause an issue?
Thanks
Will
Hello,
I wanted to try the mechanism modul, for displaying some results from 1d_system simulation in Creo (Mechanism)
I can for instance attach the displacement profil on a piston and observe then how my valve really works.
Anyway now I wanted to add the motion of spring (compression) and I found this video:
https://learningexchange.ptc.com/tutorial/2606/federn-und-d-mpfer-in-creo-mechanism
Unfortunately I can found neither the spring icon nor the force etc....
I have only the servo motor. gears, cams, belts, 3d contact
Where is this spring icon hidden?
Thanks for any tipp
Maxime
Hi,
is possible to assign to a beam element a prescribed temperature load in thermal mode? This beam was created by selecting a point and selecting a surface projection, not by selecting a line.
Hello!
I would like to use the Total Load at Point,
but I don't know how to create the point
Can You help me?
Thank you
Regard